Casing ripper



F. SWITZER CAS ING RIPPER Jan. 27, 1.931.

Filed Aug. 2. 1929 M HKM 35p erence is had to the accompanying drawings,

Patented Jan. 27, V1931 i' UNITE-D STATES FRANK sWITzER, oF INGLEWOOD, CALIFORNIA oAsINe merma Application filed August 2,

-This invention has to do with a Vwell tool and has particular reference to a device for ripping casing or pipe in awell.A

VIn the course of drilling or operating a j well, `it is sometimes necessary to cut open i or rip a casing or pipe located in the' well. Devices known as rippers have been used for this'purpose, the ordinary ripper being of the knife type in which a blade is operated to project from a body in a manner to extendv through the wall of the casing. This ordinary type of casing ripper has certain disadvantages, for instance, the blade has a comf paratively small cutting edge and therefore is rapidly dulled, the blade'of necessity projects from the body so that it is easily broken, and the character of the blade is such that it is more or less inefficient. Y

It is an object of this invention to provide a casing ripper having a rotating cutter which presents a long cutting edge.

It is another object of this invention to provide a ripper having a cutter which is particularly strong and which is mounted so that it is not easily broken.

It is another object of this invention to providea casin g ripper with a cutter simple in design and simple and inexpensive of manufacture.

The various objects and features of my invention will be best and more fully understood from the following detailed description of a typical form and application of the invention, throughout which description refin which: Y Fig. 1 is av longitudinal detailed sectional -view of the tool provided by this invention showing it in position in a well casing. Fig. 2 isa vdetailed transverse sectional view taken as indicated by line 2-2 on Fig. 1, and Fig. 3 is an enlargeddetailed sectional view showing the cutter in operative position ripping asection ofcasing. Y

. The -tool'provided by this invention in-A cludes, generally, a body 10, aV cutter 11, a carrier l2rmounting the cutter. in the body, an operating member 13 for the cutter cari. `rier, anda control, for instance, a tail piece 5 14, in connectionwith the operating member. ,Y

1929. Serial No. 382,872.

The `body 10 is an elongate member finy ishedat its upper end for connection with an operating means, for instance, a string of drill pipe 15. The body 1,0 has a longitudvina-ll dis osed Groove formed in it from one Y P n diagonally disposed or inclined with refero ence tothe longitudinal axis of the toolso that the groove is deeper at its lower end than at its upper end.

The cutter 11, in accordance with my invention, is in theform of a disc provided at its periphery with a singleecutting edge 18 and provided with a central opening 19 tov passa mounting pin y20. In the drawings I have shown the disc cutter provided at its periphery with a single continuous cutting edge 18. In the preferred form of the invention the peripheral face 18LL of the cutter 11 is beveled andthe edge 18 is at the line of joinder of the peripheral face 18a and one side 18b of the cutter. This form of cutting edge is particularly effective in ripping the casing, Theedge 18 being formed between the peripheral face and one side of the cutter is effective in piercing and cutting the casing, and in making a clean cut in the casing.

' The carrier 12 is in the form of a block slidably mounted in the groove or guideway in the body 10 and is notchedfrom its outer side Vto receive the cutter V11. The notchV 21 provided in the carrier block to receive the cutter' is made suiiicientlywide to carry the cutter with proper clearance and is made comparatively deep so that it receives asubstantial portion ofthe cutter. The cutter 11 is rotatv ably mounted in the carrier 12 on the mount-r ing pin 20'whi'ch extends through the opening.

19 in the cutter'and is carried in openings 25 provided in the block at opposite sides of the notch 21. The cutter is mounted in the carrier block so that it has a part projecting from the front. or forward side of the block a distancesufficientto cut through the well casing Y described. Themounting pin 20 whichoperatesto rotatably mount the cutter 11 in the -C when thetool is operated as hereinafter v A guide slots.

block 12 is prevented from becoming displaced from the opening 19 by the sides 16 of the groove in the body. The carrier 12 is vertically slidable in the grooves. Guide slots 30 are provided in the walls 16 of the groove in the body and pins 33 project from the block into the guide slots. The guide slots `30 are 'angularly disposed or inclined with reference to the longitudinal axis of the tool to be parallel with the bottom 17 of the guideway. in practice thepi'ns 33 -may 'be screw threaded into the carrier and projectfrom the opposite sides of the carrierinto't'he With this arrangement the carrier 12 is free to operate in the groove and the cutter 11 -is retained in the carrier sothat it is free to rotate; TheV inner end 314 of ythe block 12 is beveled or finished to set on the bottom (17 of'the guidewayas clearly shown in Fig. 1 ofthe drawings'l stheguide'slots 30 are parallel to thebottoml, the inner end 31 of the block 12 is always in engagement with the bottomll'.

rPhe operating member 13'is provided to vstart upwardioperation of thecarrier block 12 inthe guidewayand may be in the formof a rod slidably mounted in anopening 32 provided in the bottom of the'body. The operating rod Ais preferably arranged'concentrie with the body 10"and has its upper end extending' into the guidewa'y in the body toengage under the'block 1'2 and has its lower end projecting downwardly from the body. ln practice I provide means for limiting the movement of the'operating member with reference to the body, which means may'include a stop pin 40 carried by the body to cooperate with a notch 41 in the side of the operating member. The control means or ita-il piece provided in Aconnection withthe operating 4member may include two rings 50 and 51 slidable on the lower end lportion of the'operating member below the body 10, a plurality' oft-ail ipiece springs 52 connecting'the rings and bearingoutwardlyragainst the interior of the casing C and a latch 53 for latohing the upper ring in a down position.' A head 55 is'applied to the lower endof the operating member'` to prevent displacement of the tail pieceV from the'operating member.

' "In operation the `tool is lowered into the casing C with -parts in position as `shown in Fig. 1. As thel tool is lowered into place, the

, bloclr12 is at the'lower end of the guideway in Y whichcase it is V1n the Vin position and the upper ring 5001i the tail piece 'isfabove the latch 53 and isin engagement with thelower 'endof th'ebody-lO. W'hen it is desi-red to set 'thetool" 'for operation, ythe bod-y 1(1)"ismo'ved 'u'pw'ar'dlythroughv the string'of drill pipe 15 causing the' Aoperating ine'n'iber 13 -'t`o move upwardly'thrugh the rings of the'tail piece until Althe latch' vv53 engages above the upper rii'rg'O. fterthfisla'tc'hing operation downwardlmovement of the body k1O`will cause-'the operating member 13 to be moved up through the opening 32 so that it moves the cutter" carrying block 12 upwardly in the guideway. The inclination or angularity of the bottom 17 of the guideway causes the block 12 to move laterally or outwardly as it moves up through the guideway, thus causing the cutter 11 to be moved into engagement with the casing C. Y

Then the cutter has engaged the casing C 'itis no vlonger necessary for the block to be vthrough the casing causes the casing to `be ripped. The mannerin which the'cutter 11 rips or cuts the casing is clearly illustrated in Fig. 3 of the drawings. The sharpened edge 18 pierces and cuts lthe casing while the `beveled periphery of the cutter bends the vcasing away from one'side Vof the cut and formsa lip along the'cut..

When it is desired to remove'the tool 'from -t-he casing, itis pulled upwardly 'causing the cutter `carrying block to return to the'lower end of the guideWa-y. During the upward movementof theftoolout ofthe casing the'lower ring 51'of thetail piece lis in engagement with the `head 55'101-1v the klower-'end of the'operating member. f

Having; described 1 only atypical preferred form of my invention I do not wish to limit `myself to the specific details set forth, but

wish to reserve to myself any'changes' or variations that'may appear to those'skil-led4r in the art orfall within'. thescopeo'f the following claims.

Having described my invention, `Ifclaim: 1. A well casing ripper including -a body having a longitudinal guideway iwith'an inclined bottom,"and"havi`ng an openingV in the side of the g'uideway parallel' with'the bttom, a carrier slidablj'/v mounted in' the guideway in engagement with'the bottom, a disc cutter having a'bevel'edl periphery j'oi'ning'o'ne side of the cutter to form an edge, apinrotatably mounting the cutter in the carrier, anda p ln on'the carrier extending into the opening.

2. A well-casing ripper including,a' body having aflongitudinal guideway with an inclined bottom, and havingfopenings in the sides Yof the guideway with `a-n .inclinedbottom, and h'avin @openings Vin theI sidesl ofthe guideway parallel with the bottom, a'carrier sli'ldably mounted in' the guideway `i'n-eng'age- Y ment 'with the bottom, a disc cutter having a beveled periphery, a cutti'n'gedge at one edge Vof the-1 beveled periphery, "a vpin rotatably mounting the cutterin the carrier, pms'pro- 'jeeting' f'r'cm `the carrier mtu the openings,

the carrier into the openings, and means for' operating the carrier in the guideway, said means including an operating rod carried by the lower portion of the body and projecting into the guideway and a tail piece on the rod below the body. Y

4. A well casing ripper including, a body having a longitudinal guideway with an inclined bottom, and having openings in the sides of the guideway parallel with the bottom, a carrier slidably` mounted in the guideway in engagement with the bottoma disc cutter having a beveled periphery, a cutting into the carrierand extending into the openings, a disc cutter rotatably mounted on the f carrier having a beveled periphery, a cutting edge on the cutter at the line of joinder of the beveled periphery and one side of the cutter to operate longitudinally of the casing, and means for operating the carrier in the guideway. Y f

n In Witness that I claim the foregoing I have hereunto subscribed my name this 8th day of July, 1929.

` FRANK SWITZER.y

edge at one edge of the periphery, a pin rotatably mounting the cutter in the carrier, pins projecting from the carrier into the openings, and means for operating the cari rier in the guideway, said means including an operating rod carried by the lower portion of the body and projecting into the guideway, a tail piece on the rod below the body, and a control latch for operatively connecting the rod and tail piece.

5. A well casing ripper including, a body having a longitudinal guideway with an inclined bottom, and having diametrically opposite slots in the guideway parallel with the bottom, a carrier slidably mounted in the guideway in engagement with the bottom, a disc cutter having a beveled peripheral-face joining one side of the cutter to `form a single'continuous cutting edge at one edge, a pin rotatably mounting the cutter in the carrier, pins at opposite sides of the carrier slidable in the slots, and means for operating the carrier in the guideway.

Y 6. A well casing ripper including, a body having a guideway with an inclined bottom and having openings in the walls of the guideway parallel with the bottom, a carrier slidably mounted in the guideway, a disc cutter rotatably carried by the carrier the cutter having a beveled periphery, a cutting edge at the line of joinder of the beveledperiphery Y and one side ofthe cutter to operate longitudinally of the casing, pins on the carrier extending into the openings, and means for operating'the carrier.

7. A well casing ripper including, a bod)7 having a guideway with an inclined bottom and having openings in the wall of the guidewa-y parallel with the bottom, arcarrier slidable in the guideway, pins screw threaded 

